378 



ÏT. XAGAOKA. 



then, we are to explain tlie transient carrent in terms of known 

 changes of susceptibility in the directions of elongation and compres- 

 sion, we should expect the circular components of the lines of induc- 

 tion in the wire, and probably the transient current, to increase as the 

 twist is increased. But in the experiments just described, there is a 

 maximum which conies with a tolerably small amount of twist, and 

 there is always decrease of current when the angle of twist becomes 

 sufficiently great. These results on the transient current, and the 

 change of susceptibility in the directions of compression and of 

 stretching lead to contradictory conclusions. Thus it seems that the 

 peculiarities of the transient current cannot he explained in terms of 

 aeolotropic susceptibility, but some other causes must be acting in 

 producing the peculiarity mentioned above. 



In order to rind, how the transient current is affected by the 

 thickness of the wire, four specimens of nickel wire were examined 

 by the method of reversal. The angle of twist was in all cases equal 

 to ±60°. The following table gives the readings;* the curves are 

 shown in Fiff. XIV. 



* One scale division corresponds to 2.1 X 10~ 6 Coulomb. 



